test: Add ByteStreamBuffer test

The test exercises the API of the ByteStreamBuffer class in both read
and write modes, including carve out buffers.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

test/byte-stream-buffer.cpp

@@ -0,0 +1,172 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2018, Google Inc.
+ *
+ * byte_stream_buffer.cpp - ByteStreamBuffer tests
+ */
+
+#include <array>
+#include <iostream>
+
+#include "byte_stream_buffer.h"
+#include "test.h"
+
+using namespace std;
+using namespace libcamera;
+
+class ByteStreamBufferTest : public Test
+{
+protected:
+	int run()
+	{
+		std::array<uint8_t, 100> data;
+		unsigned int i;
+		uint32_t value;
+		int ret;
+
+		/*
+		 * Write mode.
+		 */
+		ByteStreamBuffer wbuf(data.data(), data.size());
+
+		if (wbuf.base() != data.data() || wbuf.size() != data.size() ||
+		    wbuf.offset() != 0 || wbuf.overflow()) {
+			cerr << "Write buffer incorrectly constructed" << endl;
+			return TestFail;
+		}
+
+		/* Test write. */
+		value = 0x12345678;
+		ret = wbuf.write(&value);
+		if (ret || wbuf.offset() != 4 || wbuf.overflow() ||
+		    *reinterpret_cast<uint32_t *>(data.data()) != 0x12345678) {
+			cerr << "Write failed on write buffer" << endl;
+			return TestFail;
+		}
+
+		/* Test write carve out. */
+		ByteStreamBuffer wco = wbuf.carveOut(10);
+		if (wco.base() != wbuf.base() + 4 || wco.size() != 10 ||
+		    wco.offset() != 0 || wco.overflow() || wbuf.offset() != 14 ||
+		    wbuf.overflow()) {
+			cerr << "Carving out write buffer failed" << endl;
+			return TestFail;
+		}
+
+		/* Test write on the carved out buffer. */
+		value = 0x87654321;
+		ret = wco.write(&value);
+		if (ret || wco.offset() != 4 || wco.overflow() ||
+		    *reinterpret_cast<uint32_t *>(data.data() + 4) != 0x87654321) {
+			cerr << "Write failed on carve out buffer" << endl;
+			return TestFail;
+		}
+
+		if (wbuf.offset() != 14 || wbuf.overflow()) {
+			cerr << "Write on carve out buffer modified write buffer" << endl;
+			return TestFail;
+		}
+
+		/* Test read, this should fail. */
+		ret = wbuf.read(&value);
+		if (!ret || wbuf.overflow()) {
+			cerr << "Read should fail on write buffer" << endl;
+			return TestFail;
+		}
+
+		/* Test overflow on carved out buffer. */
+		for (i = 0; i < 2; ++i) {
+			ret = wco.write(&value);
+			if (ret < 0)
+				break;
+		}
+
+		if (i != 1 || !wco.overflow() || !wbuf.overflow()) {
+			cerr << "Write on carve out buffer failed to overflow" << endl;
+			return TestFail;
+		}
+
+		/* Test reinitialization of the buffer. */
+		wbuf = ByteStreamBuffer(data.data(), data.size());
+		if (wbuf.overflow() || wbuf.base() != data.data() ||
+		    wbuf.offset() != 0) {
+			cerr << "Write buffer reinitialization failed" << endl;
+			return TestFail;
+		}
+
+		/*
+		 * Read mode.
+		 */
+		ByteStreamBuffer rbuf(const_cast<const uint8_t *>(data.data()),
+				      data.size());
+
+		if (rbuf.base() != data.data() || rbuf.size() != data.size() ||
+		    rbuf.offset() != 0 || rbuf.overflow()) {
+			cerr << "Read buffer incorrectly constructed" << endl;
+			return TestFail;
+		}
+
+		/* Test read. */
+		value = 0;
+		ret = rbuf.read(&value);
+		if (ret || rbuf.offset() != 4 || rbuf.overflow() ||
+		    value != 0x12345678) {
+			cerr << "Write failed on write buffer" << endl;
+			return TestFail;
+		}
+
+		/* Test read carve out. */
+		ByteStreamBuffer rco = rbuf.carveOut(10);
+		if (rco.base() != rbuf.base() + 4 || rco.size() != 10 ||
+		    rco.offset() != 0 || rco.overflow() || rbuf.offset() != 14 ||
+		    rbuf.overflow()) {
+			cerr << "Carving out read buffer failed" << endl;
+			return TestFail;
+		}
+
+		/* Test read on the carved out buffer. */
+		value = 0;
+		ret = rco.read(&value);
+		if (ret || rco.offset() != 4 || rco.overflow() || value != 0x87654321) {
+			cerr << "Read failed on carve out buffer" << endl;
+			return TestFail;
+		}
+
+		if (rbuf.offset() != 14 || rbuf.overflow()) {
+			cerr << "Read on carve out buffer modified read buffer" << endl;
+			return TestFail;
+		}
+
+		/* Test write, this should fail. */
+		ret = rbuf.write(&value);
+		if (!ret || rbuf.overflow()) {
+			cerr << "Write should fail on read buffer" << endl;
+			return TestFail;
+		}
+
+		/* Test overflow on carved out buffer. */
+		for (i = 0; i < 2; ++i) {
+			ret = rco.read(&value);
+			if (ret < 0)
+				break;
+		}
+
+		if (i != 1 || !rco.overflow() || !rbuf.overflow()) {
+			cerr << "Read on carve out buffer failed to overflow" << endl;
+			return TestFail;
+		}
+
+		/* Test reinitialization of the buffer. */
+		rbuf = ByteStreamBuffer(const_cast<const uint8_t *>(data.data()),
+					data.size());
+		if (rbuf.overflow() || rbuf.base() != data.data() ||
+		    rbuf.offset() != 0) {
+			cerr << "Read buffer reinitialization failed" << endl;
+			return TestFail;
+		}
+
+		return TestPass;
+	}
+};
+
+TEST_REGISTER(ByteStreamBufferTest)